Airsoft Mortar

[battlelava]

So I've finally got my 2 inch mortar firing, now its just time to figure out the most cheap, cost effective shell. I've done some searching on the forums, came up empty. I was originally going to launch a cup of bb's but now that i think of it, it seems to not have enough effect as say a nerf football range wise. Only problem is with a huge lack of resources. I'm not sure how i can get enough range out of a shell, while not having anyone injured or if i should just stick to raining bb's.